Monitor arm



FIG. 1 is a first perspective view of a monitor arm showing the new design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a rear elevation view thereof;

FIG. 6 is a front elevation view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof; and,

FIG. 9 is a perspective view of the monitor arm, shown with environment.

The broken lines depict portions of the monitor arm that form no part of the claimed design. 

CLAIM The ornamental design for a monitor arm, as shown and described. 